Add aria-labels to dialogs

src/client/components/AdvancedSearch.vue

@@ -32,6 +32,7 @@
     v-model="advancedSearchVisible"
     class="advanced-search-dialog"
     @close="updateFilters"
+    aria-label="Advanced search"
   >
     <header>
       <h2>ADVANCED SEARCH</h2>

src/client/components/AppHeader.vue

@@ -30,6 +30,7 @@
     <AppDialog
       v-model="downloadsVisible"
       class="downloads-dialog"
+      aria-label="Downloads"
     >
       <header>
         <h2>DOWNLOADS</h2>